Sunn hemp is an annual cover crop that can increase organic matter, fix nitrogen, grows in low fertility sandy soils, and does not harbor nematodes. It has been used extensively as a soil improvement or green manure crop in the tropics because of its ability to produce large amounts of biomass in as little as 60 to 90 days. Because of this, it has the potential to build organic matter levels and sequester carbon in a short period of time.
Key features
• Rapid growth and relatively short growing season requirement
• It grows best on well-drained soils with a pH from 5 to 7.5
• Used as a cover crop, sunn hemp can improve soil properties, reduce soil erosion, conserve soil water, and recycle nutrients
• Suited to the warm summer rainfall areas (or irrigation)
• Plant as soon as soil temperatures are higher than 16°C (October – November)